How do u make Oracle forget data buffered from previous queries?

• Quoting Rich Bromberg to All dated 09-28-94 ***
  > I have gone with the "ugly" method of running queries which will
  > retrieve enough blocks of non-benchmark data to completely flush the cache
  > prior to running each benchmark. To my knowledge, (which is limited),
  > there is no other way to clear the data buffer cache other than toggling
  > the instance.
  

Unfortunately, this is NOT a good method of flushing the cache, and in many cases, will NOT do so. In many versions of the Oracle database, the caching algorithm is smart enough to detect when enough data is being retrieved that caching is no longer a benefit and no longer use the LRU strategy. Also, some areas will remain cached regardless, such as the dictionary cache. Operating system caches and algorithms (when not bypassed by the Oracle database) compound the issue.

The bottom line is, it isn't reliable.
> I would be interesed in a more elegant solution if one exists.

The only effective solution is to shut down the database, and restart. An ineffective solution is not elegant. :) Received on Fri Sep 30 1994 - 18:24:12 CET